Tots with ADHD: It's OK to Treat

News from the Johns Hopkins Department of Psychiatry andBehavioral Sciences

Putting together a major study of children only slightly older than toddlers—it screened almost 2,000 of them—put feasibility and ethics face-to-face. Mark Riddle, however, pushed on. The results, he says, compensate for a decade of effort.

With a new spate of studies just out, the picture of ADHD and its most common medicine has come into focus for the children now under scrutiny—those age 3 to 5.

It’s the latest work from the nationwide, government-funded effort—the Preschoolers with ADHD Treatment Study (PATS)—which, because of the tender age of its subjects, has been nearly a decade in the doing.

The research, which involves Hopkins child psychiatrists, shows that stimulant (methylphenidate) therapy works and that lower doses can be used in this youngest group with attention deficit hyperactivity disorder.

“Elementary-school youngsters with ADHD are comparatively well studied,” says child psychiatrist Mark Riddle, an author on all of the new journal reports. “But we lacked much of anything concrete for their younger brothers and sisters.” And because Hopkins, like the rest of the country, is seeing more and more preschoolers with ADHD, the need for good treatment data is urgent. Gathering data in younger children also makes sense on a more basic level, since that’s typically the disorder’s onset time.

“ADHD is a huge public health issue,” says Riddle, one of the study’s planners and head of the Hopkins branch. One of the most common psychiatric disorders in children, it affects up to 8 percent of them in this country. That’s more than 4.5 million, he adds, with some 250,000 youngsters “minted” each year.

The first PATS results—appearing in 2006—showed that preschool ADHD is in some ways unique. For one thing, the youngsters need comparatively less methyl-phenidate. Tiny 1-milligram pills three times a day became the best dose for nearly a quarter of the children with uncomplicated ADHD, once side effects were factored in. Those effects were more frequent in the preschoolers and could take a slightly different tone, Riddle says, with labile, hair-trigger emotions, for example, or some children seeming “a little blunted” in a way the older ones didn’t.

As for this year’s results, the best is finding that methylphenidate works; it’s effective even through a 10-month maintenance period. Overall, children continue to act better and fit in better socially. That’s encouraging, Riddle says, because ADHD symptoms were more severe in the PATS preschoolers, the newest data show. Almost 70 percent have additional problems with behavior or communication, for example. The largest concern is slowed growth. Though not all children on the stimulant experience that, the effect is generally greater in the younger ones, averaging a yearly half-inch lag in height and three pounds in weight from norms. “If ADHD were episodic, more like depression, that would be less of an issue. But the disorder sticks around,” says Riddle, and treatment is often long term. “Parents now have to consider if it matters that children are 5'11" instead of 6 feet tall,” he adds.

Each wave of research leaves questions in its wake. Can something be done to whittle down growth loss? Would side-by-side psychosocial programs ease the need for prescriptions? Hopkins has been exploring that. PATS began, for example, with 10-week training for parents in behavior management—tactics they could use in the home to lessen problem behavior. “The parents loved it,” says Riddle, but only 7 percent of the children saw their ADHD improve. “Still, that pushes us to look for alternate therapy, if only to let us use less medicine.”